GARDAI and prison officers are investigating whether two inmates had outside help in their jailbreak.

A manhunt is under way after Romanian brothers Vasile Feier (29) and Toader Feier (23) absconded from the Grove residential area of Castlerea Prison in Co Roscommon.

Prison officers discovered the men missing when they checked their rooms at 6.30am yesterday and found a note stating: "Sorry, but we had no choice."

There have now been three high-profile jailbreaks this year, including two escapes from Loughan House in Co Cavan.

Despite the fact that the two men remained on the run from Castlerea Prison last night, gardai refused to release pictures of them.

The pair were last seen in the Grove facility, which is a low-security, semi-open part of the complex, at 11.30pm on Sunday night.

The men were jailed for stealing from parking meters in Galway. One had been served with a removal order, which would have resulted in him being sent back to Romania upon his release, expected next April.

Yesterday, prison officers used a cherry-picker machine to search for clues along the walls around the prison, which are about 25ft-high.

It is understood the pair may have had outside help in order to scale the large wall. Justice Minister Alan Shatter said this was now being investigated.

He said he was awaiting a "detailed report" on how the men had escaped from the high- security facility.

Assistance

"These are two Romanian individuals convicted for engaging in a spate of crimes in Galway. There may or may not have been assistance in their escape and that is a matter currently under investigation," he said.

Castlerea is surrounded by woods and farmland. Local farmers were asked to stay vigilant and report any suspicious activity. Gardai in Roscommon erected checkpoints at roads across the county as part of their operation to locate the men.

Vasile Feier was serving a 22-month jail sentence, while Toader Feier was sentenced to a 23- month term.

The pair, who had both lived in Dublin, were arrested in November 2011 and convicted in late January of this year after being found guilty of stealing from parking meters in Galway. They admitted driving from Dublin to Galway on previous occasions to carry out similar offences.

During their trial, they promised the judge they would return home voluntarily if she imposed a suspended sentence on them. The brothers were instead sent to jail after the judge ruled their crimes were organised.

Toader Feier has one previous conviction, imposed in the UK in 2004 for theft, while Vasile Feier has 19 previous convictions, mainly in Romania -- five relating to theft and the remainder for road traffic offences.

The Grove facility consists of houses within the prison grounds where prisoners have bedrooms and a kitchen.

However, the men would still have had to scale a perimeter wire fence around the facility before tackling the high wall which encloses the prison.